Skin cleansing compositions routinely include abrasive particles for a variety of reasons such as cleansing the skin (e.g., removal of dirt, sebum, or oil) or improving the appearance of the skin (e.g., exfoliation). Abrasive particles are commonly made from petroleum-based synthetic polymers like polystyrene or cross-linked styrene (XST) and/or polyurethane (PU), polyolefins, or waxes. Unfortunately, these petroleum-based synthetic polymers may pose long-term disposal problems and could have adverse effects on the environment.
Current market demands for more green alternatives, has led to a start in the use of biobased abrasive particles in fabric and home care products for cleaning dishes, clothes, and hard surfaces. Existing biodegradable abrasive particles that are designed for certain fields of application such as hard surface cleaning, detergents for dish or clothes, however, which require scouring of hard to remove stains on inanimate surfaces, are not generally appropriate to use on skin. These abrasive particles may be overly abrasive and may damage the skin.
Less aggressive biodegradable abrasive particles may, on the other hand, yield poor or inadequate cleansing performance as evidenced by soil or make-up remaining on the skin after use. Also in personal cleansing compositions it is desirable to have abrasive particles that are large enough to be seen and felt by the consumer, without having a gritty texture. Existing biodegradable abrasive particles, however, may have an undesirable gritty texture and may feel overly coarse. Formulators often must choose between visible, larger, but overly abrasive particles that may cause damage on the skin and gentler abrasive particles with a better sensorial feel but with inadequate cleansing efficacy and that cannot be seen by the user.
The use of biobased polymers as biodegradable abrasive particles, in skin cleansing compositions, particularly body wash cleansers, has only been minimally explored for optimal abrasive particle properties, optimal stability and optimal compatibility with other components in skin cleansing chassis. Skin cleansing compositions can be structured to suspend and stabilize dispersions of benefit agents and other materials, while maintaining physical integrity of the personal care compositions.
Structured surfactants are a useful way to provide structure. These surfactants provide stability to the composition, as well as provide lathering, cleansing, mildness and other functions typically associated with surfactant. The surfactant needs to provide structure at full strength within a cleansing composition and then upon dilution the composition should rapidly transition to free surfactant micelles that lather, clean and deposit benefit agents. If the concentration of the structured surfactant is too high or increased to boost structure, these compositions generally have reduced mildness. If the compositions are over structured, then poor lathering results. Not having enough structurant can cause instability. Furthermore, achieving a balance between these two properties in the presence of larger, shaped abrasive particles can be difficult.
Therefore, there is a need for a new skin cleansing composition, e.g. body wash composition, comprising shaped biodegradable abrasive particles, having skin cleansing and/or exfoliating benefits when applied on skin surfaces and having a sufficiently acceptable surface safety profile on skin. It is also highly desirable that the skin cleansing composition is biodegradable, preferably in addition to the abrasive particles being biodegradable. The skin cleansing composition comprising shaped abrasive particles and lower levels of structuring surfactants herein also provide compositions having proper structure when at full strength and a micellar structure upon dilution. These compositions are also mild and the particles have adequate stability, visibility and tactile properties. Such a composition has not been recognized in the art.